BACKGROUND: Atrial fibrillation is a relatively common arrhythmia often seen in patients with permanent pacemakers. In this study we aimed to assess the incidence of atrial fibrillation in patients whose pacemakers were programmed to pace in the right ventricle (VVI) and compared it with patients whose pacemakers were programmed in non-VVI mode(i.e. AAI or DDD).

MATERIAL AND METHODS: Records of the patients with permanent pacemaker or implantable-cardioverter-defibrillator were evaluated and analyzed. These patients had regular periodic follow-up evaluation over the last 10 years. (January 1, 2002 to December 31, 2012). Patient demographic, pacemaker data, pacing mode, review and analysis of arrhythmia log for occurrence of new atrial fibrillation and echocardiographic findings for left atrial size, mitral regurgitation, were analyzed and recorded. Left atrial size was classified as mild, moderate or severe enlargement, depending on the left atrial dimension.

RESULTS: Average age was 68 years. There was no gender predominance (51% male). Mean follow-up duration was 6 years and 3 months. Hispanic population represented the majority of the patients (65.4%). Majority of the devices (80.0%) were programmed as DDD pacing mode. Fifty-five patients (52.8%) did not develop atrial fibrillation. 85.7% of the patients paced in VVI-mode had atrial fibrillation while atrial fibrillation occurred in 37.4% among patients paced in non-VVI-mode. This difference was statistically significant (P<0.0001).

CONCLUSIONS: Right ventricular pacing in a VVI mode was associated with higher incidence of atrial fibrillation, mitral regurgitation and left atrial enlargement. Non-VVI based pacing demonstrated lower incidence of new onset atrial fibrillation.

Keywords: Aged, 80 and over, Atrial Fibrillation - etiology, Cardiac Pacing, Artificial - methods, Defibrillators, Implantable - adverse effects, Heart Atria - pathology, Incidence, Logistic Models, Pacemaker, Artificial - adverse effects, Texas - epidemiology